<div class="vis-editor-agg-editor-advanced-toggle">
  <a ng-click="advancedToggled = !advancedToggled">
    <i aria-hidden="true" class="fa fa-caret-down" ng-class="{'fa-caret-down': advancedToggled, 'fa-caret-left': !advancedToggled}"></i>
    Advanced
  </a>
</div>